If (x+1)2x3+x=Ax+Bx+Cx2+1, then csc−1(1A)+cot−1(1B)+sec−1C= ____
If (x+1)2x3+x=Ax+Bx+Cx2+1, then cosec−1(1A)+cot−1(1B)+sec−1C=
If 0≤x≤π2 and 81sin2x+81cos2x=30 then x is equal to